That house sounds like a death trap!
My friend’s son-in-law is in the construction business, so he quickly saw the problem on the fixer-upper he was considering when he went into the attic. All houses have vent pipes, for example, for plumbing. In this case, the water heater and furnace pipes vented into the attic rather than going out through the roof. Can you say carbon monoxide poisoning?
Admittedly, I don’t know much about construction, but in a recent example, my buyer’s inspector caught a defective water heater vent and raised the alarm. The house had recently had a new roof installed, but the roofers had failed to install flashing around the pipe where it went through the roof. Lack of proper flashing left a hole to allow in rainwater as well as the pipe itself in contact with wood. Wood and a hot pipe sound like the right combination for a house fire. It was an easy fix, and the seller wasn’t out any money as their roofer quickly returned to correct the oversight. It’s things like this that a competent inspector can find for the home buyer, as well as suggest a remedy. An inspector can also advise when it's time to call in an expert to check foundation, electrical systems, AC systems, and more.